diff --git a/testing/btest/Baseline/opt.opt-files/output b/testing/btest/Baseline/opt.opt-files/output
new file mode 100644
index 0000000000..db1bbc981f
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-files/output
@@ -0,0 +1,4 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+I should be ZAM code!
+my_test
+ZAM-code my_test 
diff --git a/testing/btest/Baseline/opt.opt-files2/output b/testing/btest/Baseline/opt.opt-files2/output
new file mode 100644
index 0000000000..896f5f18fe
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-files2/output
@@ -0,0 +1,8 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+I shouldn't be ZAM code!
+my_test
+{ 
+print I shouldn't be ZAM code!;
+}
+set_to_regex
+ZAM-code set_to_regex 
diff --git a/testing/btest/Baseline/opt.opt-files3/output b/testing/btest/Baseline/opt.opt-files3/output
new file mode 100644
index 0000000000..4a5533b63e
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-files3/output
@@ -0,0 +1,6 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+I should be ZAM code!
+my_test
+ZAM-code my_test 
+set_to_regex
+ZAM-code set_to_regex 
diff --git a/testing/btest/Baseline/opt.opt-func/output b/testing/btest/Baseline/opt.opt-func/output
new file mode 100644
index 0000000000..50aa0f4560
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-func/output
@@ -0,0 +1,9 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+I should be ZAM code!
+I shouldn't be ZAM code!
+my_test
+ZAM-code my_test 
+another_test
+{ 
+print I shouldn't be ZAM code!;
+}
diff --git a/testing/btest/Baseline/opt.opt-func2/output b/testing/btest/Baseline/opt.opt-func2/output
new file mode 100644
index 0000000000..e60a7f1160
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-func2/output
@@ -0,0 +1,9 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+I shouldn't be ZAM code!
+I should be ZAM code!
+my_test
+{ 
+print I shouldn't be ZAM code!;
+}
+another_test
+ZAM-code another_test 
diff --git a/testing/btest/Baseline/opt.opt-func3/output b/testing/btest/Baseline/opt.opt-func3/output
new file mode 100644
index 0000000000..011a85e8c4
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-func3/output
@@ -0,0 +1,7 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+Me and my buds should be ZAM code!
+that includes me!
+my_test
+ZAM-code my_test 
+another_test
+ZAM-code another_test 
diff --git a/testing/btest/Baseline/opt.opt-no-files/.stderr b/testing/btest/Baseline/opt.opt-no-files/.stderr
new file mode 100644
index 0000000000..ba158c1e5e
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-no-files/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+fatal error: no matching functions/files for C++ compilation
diff --git a/testing/btest/Baseline/opt.opt-no-func/.stderr b/testing/btest/Baseline/opt.opt-no-func/.stderr
new file mode 100644
index 0000000000..ba158c1e5e
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-no-func/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+fatal error: no matching functions/files for C++ compilation
diff --git a/testing/btest/Baseline/opt.opt-no-func2/.stderr b/testing/btest/Baseline/opt.opt-no-func2/.stderr
new file mode 100644
index 0000000000..ba158c1e5e
--- /dev/null
+++ b/testing/btest/Baseline/opt.opt-no-func2/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+fatal error: no matching functions/files for C++ compilation
diff --git a/testing/btest/opt/opt-files.zeek b/testing/btest/opt/opt-files.zeek
new file mode 100644
index 0000000000..c311f6359f
--- /dev/null
+++ b/testing/btest/opt/opt-files.zeek
@@ -0,0 +1,15 @@
+# @TEST-EXEC: zeek -b -O ZAM --optimize-files='opt-files' %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+# Tests that we can selectively pick this file.
+
+function my_test()
+	{
+	print "I should be ZAM code!";
+	}
+
+event zeek_init()
+	{
+	my_test();
+	print my_test;
+	}
diff --git a/testing/btest/opt/opt-files2.zeek b/testing/btest/opt/opt-files2.zeek
new file mode 100644
index 0000000000..576680cae9
--- /dev/null
+++ b/testing/btest/opt/opt-files2.zeek
@@ -0,0 +1,16 @@
+# @TEST-EXEC: zeek -b -O ZAM --optimize-files='base/utils' %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+# Tests that we can selectively pick a group of files but not this one.
+
+function my_test()
+	{
+	print "I shouldn't be ZAM code!";
+	}
+
+event zeek_init()
+	{
+	my_test();
+	print my_test;
+	print set_to_regex;
+	}
diff --git a/testing/btest/opt/opt-files3.zeek b/testing/btest/opt/opt-files3.zeek
new file mode 100644
index 0000000000..588c633c8d
--- /dev/null
+++ b/testing/btest/opt/opt-files3.zeek
@@ -0,0 +1,16 @@
+# @TEST-EXEC: zeek -b -O ZAM --optimize-files='base/utils' --optimize-files='opt-files3' %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+# Tests that we can selectively pick a group of files *and* this one.
+
+function my_test()
+	{
+	print "I should be ZAM code!";
+	}
+
+event zeek_init()
+	{
+	my_test();
+	print my_test;
+	print set_to_regex;
+	}
diff --git a/testing/btest/opt/opt-func.zeek b/testing/btest/opt/opt-func.zeek
new file mode 100644
index 0000000000..6594cffe34
--- /dev/null
+++ b/testing/btest/opt/opt-func.zeek
@@ -0,0 +1,22 @@
+# @TEST-EXEC: zeek -b -O ZAM --optimize-func='my_test' %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+# Tests that we can selectively a given function.
+
+function my_test()
+	{
+	print "I should be ZAM code!";
+	}
+
+function another_test()
+	{
+	print "I shouldn't be ZAM code!";
+	}
+
+event zeek_init()
+	{
+	my_test();
+	another_test();
+	print my_test;
+	print another_test;
+	}
diff --git a/testing/btest/opt/opt-func2.zeek b/testing/btest/opt/opt-func2.zeek
new file mode 100644
index 0000000000..c503479905
--- /dev/null
+++ b/testing/btest/opt/opt-func2.zeek
@@ -0,0 +1,23 @@
+# @TEST-EXEC: zeek -b -O ZAM --optimize-func='another_test' %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+# Tests that we can selectively a bunch of functions (event handlers),
+# but not every function.
+
+function my_test()
+	{
+	print "I shouldn't be ZAM code!";
+	}
+
+function another_test()
+	{
+	print "I should be ZAM code!";
+	}
+
+event zeek_init()
+	{
+	my_test();
+	another_test();
+	print my_test;
+	print another_test;
+	}
diff --git a/testing/btest/opt/opt-func3.zeek b/testing/btest/opt/opt-func3.zeek
new file mode 100644
index 0000000000..15f49987b1
--- /dev/null
+++ b/testing/btest/opt/opt-func3.zeek
@@ -0,0 +1,23 @@
+# @TEST-EXEC: zeek -b -O ZAM --optimize-func='my_test' --optimize-func='another_test' %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+# Tests that we can selectively a bunch of functions (event handlers),
+# and also call out an additional function.
+
+function my_test()
+	{
+	print "Me and my buds should be ZAM code!";
+	}
+
+function another_test()
+	{
+	print "that includes me!";
+	}
+
+event zeek_init()
+	{
+	my_test();
+	another_test();
+	print my_test;
+	print another_test;
+	}
diff --git a/testing/btest/opt/opt-no-files.zeek b/testing/btest/opt/opt-no-files.zeek
new file mode 100644
index 0000000000..36a22c4c5e
--- /dev/null
+++ b/testing/btest/opt/opt-no-files.zeek
@@ -0,0 +1,10 @@
+# @TEST-EXEC-FAIL: zeek -b -O ZAM --optimize-files='Xopt-files' %INPUT
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff .stderr
+
+# Make sure that if --optimize-files is specified but there are no matching
+# files, that's caught as an error.
+
+event zeek_init()
+	{
+	print zeek_init;
+	}
diff --git a/testing/btest/opt/opt-no-func.zeek b/testing/btest/opt/opt-no-func.zeek
new file mode 100644
index 0000000000..88b8d6de47
--- /dev/null
+++ b/testing/btest/opt/opt-no-func.zeek
@@ -0,0 +1,10 @@
+# @TEST-EXEC-FAIL: zeek -b -O ZAM --optimize-files='my_func' %INPUT
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff .stderr
+
+# Make sure that if --optimize-func is specified but there are no matching
+# functions, that's caught as an error.
+
+event zeek_init()
+	{
+	print zeek_init;
+	}
diff --git a/testing/btest/opt/opt-no-func2.zeek b/testing/btest/opt/opt-no-func2.zeek
new file mode 100644
index 0000000000..84d09b90fe
--- /dev/null
+++ b/testing/btest/opt/opt-no-func2.zeek
@@ -0,0 +1,14 @@
+# @TEST-EXEC-FAIL: zeek -b -O ZAM --optimize-files='my_func' %INPUT
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff .stderr
+
+# Make sure that --optimize-func anchors the regex.
+
+function my_func2()
+	{
+	print "I shouldn't match!";
+	}
+
+event zeek_init()
+	{
+	print zeek_init;
+	}